Contrary to traditional practice, it is necessary to make clear, well in advance, where it is proposed to attack. When you do attack, do so with overwhelming force - operation Moshtarak involves some 15,000 NATO and Afghan troops, as against less than 1000 Taliban.
This does of course mean that the majority of the Taliban will melt away before the fighting starts, leaving only token resistance (although, unfortunately, there will still be a few casualties). Nevertheless, the allies should be able to achieve their immediate objectives without excessive difficulty, enabling the commanders to make suitable comments to the media about the favourable progress. Furthermore, the media will get lots of pictures of helicopter gunships and soldiers dressed in battlegear.
In the longer term, it may be difficult to hold on to the areas that have been seized. But that can be left to the Afghan troops and the Afghan police. But, by then, the media cameras will have moved on, while the American and British troops will have returned to base. The name of Marjah can once again be consigned to forgotten history.
Because it's appearances that matter, isn't it?